Definition & Etiology
Definition
Increase in haemoglobin with elevated haematocrit (>0.56 in women, >0.6 in men) Can be absolute or apparent erythrocytosis
Etiology
Absolute erythrocytosis:
- Primary: Polycythaemia rubra vera (PRV) – a neoplastic proliferation of BM alongside a possible increase in WCC & Plt
- Secondary: EPO-related causes – secondary to chronic hypoxia from chronic lung disease and from certain kidney issues – Idiopathic cases
Apparent erythrocytosis:
Low plasma volume related – secondary to thiazide diuretics, heavy smokers, alcohol use, obesity & HTN